The 11th U.S. Circuit Court of Appeals ruled on Thursday that Siegelman has met the legal standard necessary to allow him to be free from prison while he seeks to show he was wrongly convicted.
The former Democratic governor is serving a sentence of more than seven years for six bribery-related counts and one obstruction count. He began serving the term last June.
Earlier on Thursday, the House Judiciary Committee asked the Justice Department to temporarily release Siegelman from prison in early May to testify before Congress about possible political influence over his prosecution.
A spokeswoman for the committee said Siegelman would travel to Washington under guard of the U.S. Marshals Service. She said Committee Chairman John Conyers, a Michigan Democrat, believes Siegelman could provide important information about Justice Department practices under President Bush.
"The chairman has determined it would be appropriate to hear from Mr. Siegelman himself and believes he would have a lot to add to the committee's investigation into selective prosecution," spokeswoman Melanie Roussell said.
The Justice Department had no immediate comment.
Democrats last year began reviewing Siegelman's 2006 corruption conviction as part of a broader investigation into allegations of political meddling in Justice affairs by the Bush administration.
Justice and the federal prosecutors who handled the prosecution have denied any political influence, emphasizing that Siegelman was convicted by a jury. But critics, including about 50 former state attorneys general, have called for a review and said the case raises a number of questions.
The effort gained momentum after a Republican lawyer who had volunteered for Siegelman's re-election opponent - current Republican Gov. Bob Riley - said she overheard conversations suggesting that former White House adviser Karl Rove was talking with Justice officials about Siegelman's prosecution.
Last month, "60 Minutes" reported thatagainst Siegelman said that prosecutors met with him some 70 times and had him repeatedly write out his testimony because they were frustrated with his recollection of events.
Siegelman was elected governor in 1998 and served one term before narrowly losing re-election to Riley in 2002, as reports of corruption investigations clouded Siegelman's administration.
Siegelman was originally indicted in 2004 on charges of conspiring to rig bids on state Medicaid contracts. Prosecutors dropped the case, however, after a judge ruled there was insufficient evidence to support key charges.
Siegelman was indicted again a year later in a separate bribery and corruption case.
In June 2006, he was convicted on six bribery-related and one obstruction of justice charge. He began serving his sentence last June.
Siegelman was accused of appointing then-HealthSouth CEO Richard Scrushy to an important hospital regulatory board in exchange for Scrushy arranging $500,000 in disguised contributions to Siegelman's campaign for a statewide lottery. Siegelman was also convicted of a separate obstruction of justice charge concerning $9,200 he received from a former lobbyist to help with the purchase of a motorcycle.
A member of Siegelman's defense team, which is working on his appeal, said Thursday the former governor already has agreed to testify to Congress.
"They seem to think it's critical to straighten out the Justice Department to have him shed whatever light he can," attorney Vince Kilborn said. "He's delighted to cooperate. There are no restrictions on questions they can ask him."